Amp Annealer Changing POI

[robert rex]

I've been reloading a Winchester 270 with 117 grain hammer hunters, using Hornaday brass. I'm full length sizing and using a mandrel to size the necks, and found a great load using 58 grains of R16, .030 off jam....pretty much one jagged hole. With components so scarce, and with dreams of superhuman consistency, I purchased an AMP Annealer. Well, my perfect groups spread out like an egg hitting the floor. Not terrible, but from excellent to say 1 1/4 moa. Should I restart working the load back up to see if the nodes changed....or just mess a bit with the seating depth a bit. Anyone else experience this when they started annealing? I'd hate to re-work the loads on all my rifles...not pretty.

 

[Ckleeves]

Can’t say I have seen that before. What did bullet seating feel like with the annealed vs unannealed cases? Could be a change in neck tension.

Was the ragged hole load well proven? If it wasn’t you could have gotten a liar group that shot amazing one day but won’t repeat.

Any changes in velocity?

 

[robert rex]

Can’t say I have seen that before. What did bullet seating feel like with the annealed vs unannealed cases? Could be a change in neck tension.

Was the ragged hole load well proven? If it wasn’t you could have gotten a liar group that shot amazing one day but won’t repeat.

Any changes in velocity?

They felt exactly the same when seated. The load was proven many times at the range...I was kind of proud to have worked up a load that was consistently good, and really sad to see it deteriorate. The less than stellar outcome happened yesterday, and I didn't have my Magnetospeed with me, but pre-annealed loads were in the 3340-3350 range, single digit SD no wild ES.

 

[Pdvdh]

Shoot'em with the Magneto and check MV again.
Got any cases that haven't been annealed? Choot'em if so...

 

[Rflamm250]

I have not noticed groups opening up after annealing. What I have noticed is I usually have to make some very minor adjustments to my die due to the brass having less spring back after annealing.

 

[Deans]

I have read elsewhere that over annealing can cause groups to open. The second loading groups came back together. You may want to adjust the timing on your annealer.

 

[Dmagna]

Did you resize after annealing?

 

[robert rex]

Did you resize after annealing?

Yes, full length resizing. Hard to over anneal with an AMP. I'm thinking I'll take the ones that were annealed, which shot the looser group, and not anneal them resize them and see if the group comes back together.

 

[LaHunter]

Or just send the annealing machine back or sell it??? Seems like you had really good performance already.

 

[Mikecr]

You should develop with brass in it's final condition.
In this case -with annealing -or without annealing.

 

[Mikecr]

You should develop with brass in it's final condition.
In this case -with annealing -or without annealing.

 

[Rflamm250]

Yes, full length resizing. Hard to over anneal with an AMP. I'm thinking I'll take the ones that were annealed, which shot the looser group, and not anneal them resize them and see if the group comes back together.

I actually did recently. Used the amp , Aztec mode. Burned one and used the produced code. Annealed 200 pcs . Seated bullet with .02 interference. I could then push the bullet deeper with my fingers

 

[Bob Wright]

I would check your mandrel diameter. Annealed brass vs work hardened brass are sizing necks larger after annealing. Less springback.

 

[JMW67]

what Bob said and the hammer bullets like a little more neck tension is what I have found to the point alot of folks are crimping them I just increased neck tension and closed groups up